siemens. answers. >>> talk about a close call. >> oh, my god. >> stand back. stand back, stand back. >> a group of tourists barely avoided an attack by a great white shark. look at this. it happened off the coast of south africa. a pair of divers entered into a diving cage hoping to catch a glimpse of the predator. well, they got more than they bargained for. the shark ignored the bait and instead stuck its head into the cage trying to get the people inside. >> stand back. stand back. here it is in slow motion. wow. it almost appears to get ahold of one of the divers but they were able to quickly swim to the bottom of the cage until the shark swam away. incredibly neither of the divers was injured. al dove is director of research and conservation at the georgia aquarium and joins me now by phone. so al, jack diving, a really huge tourist attraction in south africa, i would imagine other places and other parts of the world. it's dangerous. >> it is dangerous to some degree. certainly there's a thrill-seeking element involved, but you have to question the wisdom